# Remove a vdev from a zpool

`https://www.truenas.com/community/threads/remove-a-vdev-from-a-zpool.35608/`

Funny how two minds can think alike, that is exactly what I did and I like to write it down for further generations to come (or myself if I do it again) ;)

```
# zpool status -v tank
pool: tank
state: ONLINE

NAME STATE READ WRITE CKSUM
tank ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
gptid/e41b2476-22bd-11e2-ac2d-3cd92b06cdcb ONLINE 0 0 0
gptid/e4c521be-22bd-11e2-ac2d-3cd92b06cdcb ONLINE 0 0 0
mirror-1 ONLINE 0 0 0
gptid/b4580a46-2fcd-11e5-af9d-3cd92b06cdcb ONLINE 0 0 0
gptid/b51e45b8-2fcd-11e5-af9d-3cd92b06cdcb ONLINE 0 0 0
```


First you have to remove one of the new drives from the mirror.

`zpool detach tank /dev/gptid/b51e45b8-2fcd-11e5-af9d-3cd92b06cdcb`

Then, create a new pool on the just detached drive

`zpool create sonne /dev/gptid/b51e45b8-2fcd-11e5-af9d-3cd92b06cdcb`

Now replicate all your data from the old filesystem to the new. (snd/rcv can take a while)

```
zfs snapshot -r tank@nas_backup
zfs send -Rv tank@nas_backup | zfs receive -Fv sonne
```

To make FreeNAS aware of your newly created filesystem

`zfs export sonne`

Then, while in the WebGUI, click "Storage -> Import Volume" to import it.
Since I found no other way, I manually changed all path (user home dir, shares etc.) to their new values.
Reboot.

Then comes the scary part

```
zpool destroy tank
zpool attach sonne gptid/b51e45b8-2fcd-11e5-af9d-3cd92b06cdcb gptid/b4580a46-2fcd-11e5-af9d-3cd92b06cdcb
```

Then the resilvering will set in. Done.

**Reminder:** During the whole process, there is no redundancy. If any drive fails, your data is gone.

*By the way, if anyone knows how to tell FreeNAS (or ZFS) to not use gptid in "zpool status", instead make it look like https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/zfs-zpool.html, please PM me.*